JP2006134889A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent exoergic loss, enlargement, difficulty in restarting, noise and breakdown of insulation. <P>SOLUTION: The projector is provided with a light source apparatus containing a discharge lamp Ld containing 0.15mg or more of mercury per volume for 1 cubic millimeter of discharging space, a pair of electrodes E1 and E2 with spacing between the electrodes at 2.5mm or less which are mainly for discharging and installed facing each other and an auxiliary electrode Et which is other than the electrodes mainly for discharging and provided not in contact with the discharge space mainly for discharging. A power supply circuit Bx supplying discharge current to the electrodes E1 and E2 which are mainly for discharging and a starter Ue producing high voltage between one of the both polarity electrodes E1 and E2 mainly for discharging and the auxiliary electrode Et are connected in the light source apparatus. At least a high voltage producing part Ub containing a high voltage transformer Te of the starter circuit Ue is separated from a power supply circuit (By). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector having a light source device using a high-pressure mercury discharge lamp.

In a light source device for an optical device such as a liquid crystal projector or a DLP (registered trademark of Texas Instruments) projector, a high-intensity discharge lamp (HID lamp) is used.
However, in recent years, in order to make the optical device bright, it has been required to increase the amount of mercury enclosed in the discharge lamp as compared with the conventional art. In this type of discharge lamp, it is necessary to start a discharge by generating a high voltage using a starter at the time of starting, and causing a dielectric breakdown in the discharge space.

  The configuration of a conventional discharge lamp light source device is shown in FIG. In a light source device for an optical device, a starter (Ui) that applies a high voltage between the electrodes (E1, E2) of both electrodes is usually used as a starter. In this system, since the secondary winding (Si) of the high voltage transformer (Ti) of the starter is connected in series with the lamp (Li), the discharge starts and the function of the starter (Ui) is no longer necessary. Nevertheless, the discharge current supplied to the lamp (Li) must flow through the high-voltage transformer secondary winding (Si) having a large number of turns. In order to suppress the generation of heat loss in the winding (Si) at this time, it is necessary to increase the wire diameter of the winding, and there is a problem that an increase in the size and weight of the starter (Ui) cannot be avoided.

As a measure for solving this problem, it is possible to use an external trigger method which is frequently used for triggering a flash lamp. In this method, an auxiliary electrode is provided in addition to the main discharge, that is, the first and second electrodes for arc discharge after starting, and a high voltage is applied between the auxiliary electrode and the first or second electrode. Applied to generate plasma in the discharge space by dielectric barrier discharge, and using this plasma as a seed, the main discharge is caused by the voltage (no-load open voltage) applied in advance between the first electrode and the second electrode. It is what is started.
With this structure, since the discharge current of the lamp does not flow in the primary and secondary windings of the starter high-voltage transformer after the start of discharge of the lamp, the primary and secondary of the starter high-voltage transformer There is no heat loss in the secondary winding, and it is possible to avoid an increase in the size and weight of the starter.

However, in a discharge lamp with a large amount of enclosed mercury, when the lamp is at room temperature, the pressure in the discharge space is low because mercury is condensed, so that it can be started relatively easily. If the elapsed time is short and the lamp is hot, there is a problem that restart (hot restart) is difficult because mercury is vaporized and the pressure in the discharge space is high.
The problem that is difficult to restart under hot restart conditions is an important performance problem for an optical apparatus such as a projector that affects the usability of the user of the apparatus. And with the recent increase in the amount of enclosed mercury, the problem of difficulty in restartability is becoming more serious for the external trigger system.

  On the other hand, conventionally, the discharge lamp (Li) and the power supply device (Ni) are connected by power supply lines (K1, K2), and the starter (Ui) for starting the discharge lamp (Li) is on the power supply device side (Ni). It was installed. The starter needs to generate a high voltage (Ui). When the starter (Ui) generates a pulse high voltage, the power supply lines (K1, K2) are charged to a high voltage in a short time and radiate intense noise.

  Further, due to the capacitance formed between the power supply lines (K1, K2) and the surrounding conductor and the inductance of the power supply lines (K1, K2), the pulse high voltage is distorted, and the lamp electrode (E1 , E2), the increase in voltage is diminished, and in order to obtain the pulse voltage necessary for starting the discharge lamp, more energy than necessary is supplied from the starter (Ui) to the feeder lines (K1, K2). In addition, since the pulse width increases due to the pulse high voltage rounding, the high voltage transformer (Ti) of the starter and the insulation coating of the feeder lines (K1, K2) are not intended. There is a risk that breakdown may increase and reliability may be lowered.

On the other hand, in the case of a starter called a DC starter that generates a high voltage that rises relatively slowly, the higher the voltage and the longer the voltage application time, the easier the dielectric breakdown phenomenon occurs. There was a problem that the possibility of dielectric breakdown further increased.
Examples of conventional inventions and devices for starting a high-pressure discharge lamp using an external trigger method include those described in Patent Document 1 and Patent Document 2.
The idea of Patent Document 1 describes a configuration in which a coil that generates a magnetic force with a lamp current of a high-pressure mercury lamp is provided and the operation of a starter circuit that generates a high voltage at an auxiliary electrode is controlled by the magnetic force.
Further, the invention of Patent Document 2 describes a configuration in which auxiliary electrodes (external electrodes) are arranged close to each other with a distance of several mm on a lamp such as a high-pressure mercury lamp.
However, in these conventional inventions and devices, guidelines and conditions for making a light source device that can be restarted while avoiding the problem of dielectric breakdown in unintended portions even in the hot restart described above are completely considered. It wasn't.
Japanese Utility Model Publication No. 37-8045 JP-A-5-54983

  The present invention reduces the conventional problem of the light source device in the projector, i.e., the voltage increase between the lamp electrodes caused by the rounding of the starter pulse high voltage, which is a problem in the starter that generates a high voltage pulse. Adverse effects and noise radiation problems can be suppressed, the possibility of undesired insulation breakdown occurring, and the starter's Due to problems that cannot be avoided in terms of size and weight, problems that are difficult to restart when the lamp has been hot for a short time, and capacitive coupling between the feeder and surrounding conductors, The purpose is to solve the problem of having to release more energy than necessary toward the electric wire.

In order to solve this problem, the invention according to claim 1 of the present invention is a pair of main components including mercury of 0.15 mg or more per cubic millimeter of the volume of the discharge space (12) and having an electrode interval of 2.5 mm or less. A discharge lamp (Ld) in which electrodes (E1, E2) for discharge are arranged opposite to each other and a power supply circuit (Bx) for supplying a discharge current to the electrodes (E1, E2) for main discharge are connected. In a projector having a light source device, an auxiliary electrode (Et) other than the main discharge electrode is provided so as not to be in contact with the discharge space (12) for the main discharge, and the bipolar electrodes for the main discharge ( A starter circuit (Ue) for generating a high voltage is connected between any one of E1 and E2) and the auxiliary electrode (Et), and includes at least a high voltage transformer (Te) of the starter circuit (Ue). The high voltage generator (Ub) is separated from the power feeding circuit (By).
The invention of claim 2 of the present invention is characterized in that the lamp (Ld) and at least the high voltage transformer (Te) of the starter are configured as an integral unit.

In the case of the external trigger method, in order to start the original main discharge, a high voltage applied between the first electrode (E1) or the second electrode (E2) and the auxiliary electrode (Et), or Simply increasing only one of the no-load open-circuit voltages cannot increase the startability.
That is, it is necessary to apply the high voltage and the no-load open voltage having an appropriate balance according to the lamp condition such as the elapsed time after the light is turned off, that is, the temperature at the time of starting. Even when the balance is maintained, depending on the elapsed time after the light is turned off, either or both of the high voltage and the no-load open-circuit voltage to be applied become very high. It can be seen that there is a risk of dielectric breakdown.
Therefore, under the limit of the dielectric strength that can be imparted to the light source device, which is imposed from the viewpoint of compactness and economy required for the target optical device, the shortest elapsed time after extinction that can be restarted Will exist.

  Based on the above matters, first, the experiment conducted by the inventors will be described with reference to FIGS. Argon and 0.2 nanomole bromine per cubic millimeter of discharge space, 0.15 mg mercury per cubic millimeter of discharge space, between the first and second bipolar electrodes for the main discharge The experimental results using a lamp with a distance (AL) of 0.6 to 2.5 mm are shown in FIGS.

  1 shows a case where the no-load open voltage (Vopn) is 280V, and FIG. 2 shows a case where the no-load open voltage (Vopn) is 350V. As shown in FIG. 3, the experiment was performed by connecting a DC power source (Mx), a power feeding circuit (Bx), and a starter (Ue) to a lamp (Ld). However, in order to give an independent applied voltage to the primary winding (Pe) of the high voltage transformer of the starter, a variable voltage source (Vp) is connected, and a no-load open voltage (Vopn) is applied to the lamp (Et). In this state, a high voltage pulse generated by the starter (Ue) was applied between the first electrode (E1) and the auxiliary electrode (Et).

When the high voltage pulse is applied, the lamp (Ld) is turned on for 4 minutes in advance, and after the light is turned off, the voltage of the variable voltage source (Vp) is gradually increased from a low value, and the lamp (Ld) The time until the start was successful, that is, the restart impossible time (Trst) was measured (FIG. 1R> 1, the vertical axis in FIG. 2).
After the lamp (Ld) is extinguished, the secondary winding (Se) of the high voltage transformer of the starter and the auxiliary electrode (Et) of the lamp are once disconnected, and the secondary side of the high voltage transformer of the starter is disconnected. The starter (Ue) is operated in a load state without changing the voltage of the variable voltage source (Vp) from that when the lamp (Ld) is successfully started, and the secondary winding of the high voltage transformer of the starter ( The generated voltage of Se) was measured using an oscilloscope, and this measured value was taken as the peak voltage (Vtrg) of the high voltage pulse (horizontal axis in FIGS. 1 and 2). However, the conditions under which the start success rate of the lamp (Ld) is less than 50% in the region where the peak voltage (Vtrg) of the high voltage pulse is lower are not plotted in FIGS.

That is, in each of the conditions of the no-load open-circuit voltage and the interelectrode distance shown in FIGS. 1 and 2, there was a case where the start-up succeeded by chance even when the peak voltage (Vtrg) of the high voltage pulse was lower. Such an example is considered to be a variation in the phenomenon, and therefore, the plot was not plotted for the condition where the success rate was generally less than 50% when multiple attempts were made.
1 and 2, the peak voltage (Vtrg) and non-restartable time (Trst) of the high voltage pulse corresponding to the left end of the plot point group for each of the distances (AL) between the electrodes for main discharge are The voltage Vtmin required for starting the main discharge and the maximum value Trmax of the non-restartable time are given to the lamp in the room temperature state.

  As can be immediately pointed out from FIGS. 1 and 2, the higher the peak voltage (Vtrg) of the high voltage pulse, the shorter the non-restartable time (Trst) for each of the distances (AL) between the electrodes for main discharge. In addition, the higher the peak voltage (Vtrg) of the high voltage pulse is, the higher the peak voltage (Vtrg) of the high voltage pulse is increased to twice the voltage Vtmin necessary for starting the main discharge in the lamp at room temperature. Is greatly shortened, and even if the peak voltage (Vtrg) of the high voltage pulse exceeds 5 times the voltage Vtmin required to start the main discharge in the lamp at room temperature, The non-startable time (Trst) is that further shortening cannot be expected.

  More specifically, for example, when attention is paid to the data relating to the distance between electrodes of 1.2 mm in FIG. 1, the voltage Vtmin necessary for starting the main discharge in the lamp at room temperature is 4.1 kV. In the region from Vtmin to the portion corresponding to 8.4 kV, which is twice that, the non-restartable time (Trst) decreases smoothly in response to the increase in the peak voltage (Vtrg) of the high voltage pulse. However, in the region exceeding 5 times Vtmin, even if the peak voltage (Vtrg) of the high voltage pulse is increased, the plot points are almost horizontal, so the non-restartable time (Trst) does not decrease. . This is also true for data related to other interelectrode distances. Further, this situation is the same regardless of the value of the no-load open circuit voltage (Vopn).

  Therefore, if the peak voltage (Vtrg) of the high voltage pulse is less than twice the voltage Vtmin required to start the main discharge in the lamp at room temperature, the re-starting can be performed when the conditions for the hot restart are considered. The possibility of improving the startability is not effectively utilized, and conversely, even if the voltage Vtmin required to start the main discharge in the lamp at room temperature is increased more than 5 times, It can be seen that the possibility of improving restartability under hot restart conditions is hardly expected, but rather promotes the risk of dielectric breakdown in the unintended portion described above.

  When the amount of mercury contained in the discharge space is further increased, the pressure in the discharge space is further increased due to vaporization of mercury, so that restartability under the hot restart conditions becomes worse. It is desirable that the voltage Vtmin required for starting the main discharge is at least twice or more, but even if it exceeds 5 times, the risk of dielectric breakdown in the unintended part is promoted. It is similar that the possibility of improving restartability is hardly expected.

When attention is paid to the data relating to the distance between electrodes of 1.2 mm in FIG. 1, the voltage Vtmin required to start the main discharge in the lamp at room temperature, that is, 4.1 kV, is 2.5 times that of 10. In the region of 25 kV or 3 times less than 12.3 kV, the non-restartable time (Trst) is still decreased corresponding to the increase of the peak voltage (Vtrg) of the high voltage pulse. The voltage (Vtrg) is preferably about 2.5 times or 3 times or more than Vtmin.
In addition, in the region exceeding 16.4 kV, which is 4 times Vtmin or 18.45 kV, which is 4.5 times, the effect of decreasing the non-restartable time (Trst) with respect to the increase of the peak voltage (Vtrg) of the high voltage pulse is slow. Therefore, it is desirable that the peak voltage (Vtrg) of the high voltage pulse is 4 times or less than 4.5 times Vtmin.

As described above, by the external trigger method, after the discharge of the lamp (Ld) is started, the primary winding (Pe) and the secondary winding (Pe) of the high voltage transformer (Te) of the starter (Ue) Since the discharge current of the lamp (Ld) does not flow in Se), heat loss is generated in the primary winding (Pe) and secondary winding (Se) of the high voltage transformer (Te) of the starter (Ue). Without increasing the size and weight of the starter (Ue).
Therefore, if the starter (Ue) generates a voltage 2 to 5 times the voltage required to start the main discharge in the lamp at room temperature, it can be restarted even under the hot restart condition. Further, the light source device can be realized in which the risk of dielectric breakdown in an unintended part is suppressed and the starter is not increased in size and weight.

Next, the invention of claim 1 will be described with reference to FIG.
By separating the high voltage generation unit (Ub) including at least the high voltage transformer (Te) of the starter circuit (Ue) from the power supply circuit unit (By), the secondary side circuit unit of the high voltage transformer (Te) and the auxiliary circuit unit are separated. The length of the current path for connection with the electrode (Et) can be shortened. This reduces the capacitance formed between the current path portion for connection between the secondary side circuit portion of the high-voltage transformer (Te) and the auxiliary electrode (Et) and the surrounding conductor, The inductance of the current path can be reduced.

  Therefore, when the starter generates a pulse high voltage, the voltage (E1, E2) between the lamp electrodes increases due to the rounding of the pulse high voltage due to the presence of the capacitance and inductance of the current path. The problem of having to reduce the adverse effects of being attenuated and releasing more energy than necessary is solved, and the pulse high voltage is rounded to widen the pulse width and cause dielectric breakdown in unintended parts The possibility can be suppressed.

  Since the length of the current path for connecting the secondary side circuit portion of the high voltage transformer (Te) and the auxiliary electrode (Et) can be shortened and the loop area can be reduced, the problem of noise radiation is suppressed. be able to. Furthermore, since the length of the connection line between the starter and the auxiliary electrode (Et) is short, even in the case where the starter generates a high voltage in which the voltage rises relatively slowly, The possibility of dielectric breakdown occurring can be suppressed.

Next, the invention of claim 2 will be described.
The high-voltage transformer (Te) of the starter that generates a high voltage inevitably deteriorates in insulation performance as the number of uses increases. On the other hand, the lamp (Ld) has a lifetime, and it is essential to replace it within a finite use time. By configuring the lamp (Ld) and at least the high voltage transformer (Te) of the starter in an integral unit, when replacing the lamp due to the lamp life, the high voltage transformer (Te) of the starter is also As a result, the risk of dielectric breakdown due to the deterioration of the insulation performance of the high voltage transformer (Te) of the starter can be prevented.

Further, it is advantageous to shorten the length of the connection line between the starter and the auxiliary electrode (Et), and the possibility of the occurrence of dielectric breakdown in the unintended part is suppressed. Even in the case of generating a pulse high voltage, it is advantageous in suppressing the above-described problem of noise radiation.
In this case, the lamp replacement operation can be simplified by integrating with the optical means for directing the light emitted from the lamp (Ld) in a specific direction, such as a concave mirror.

According to the invention described in claim 1 of the present application, there is an adverse effect that an increase in the voltage between the lamp electrodes caused by the rounding of the starter pulse high voltage, which is a problem in the case of a starter that generates a high voltage pulse, is reduced. The problem of radiating noise can be suppressed. Further, it is possible to further suppress the possibility of dielectric breakdown occurring at unintended portions.
According to the second aspect of the present invention, in addition to the effect of the first aspect of the invention, it is possible to prevent the risk of dielectric breakdown due to the deterioration of the insulation performance of the high voltage transformer of the starter. it can.
In addition, if the starter (Ue) generates a voltage 2 to 5 times the voltage necessary for starting the main discharge in the lamp at room temperature, the restartability can be achieved even under hot restart conditions. In addition, the risk of dielectric breakdown in unintended portions is suppressed, and a light source device that avoids an increase in size and weight of the starter can be realized.

  FIG. 4 is a diagram showing a simplified configuration of the light source device of the present invention. The step-down chopper type power supply circuit (Bx) is connected to the PFC. In the power supply circuit (Bx), a current from a DC power source (Mx) is turned on / off by a switching element (Qx) such as an FET, and the smoothing capacitor (Cx) is charged through the choke coil (Lx).

  The discharge current flowing between the electrodes (E1, E2) for the main discharge of the lamp (Ld), the voltage between the electrodes (E1, E2) for the main discharge, or the lamp power which is the product of these currents and voltages is Then, a gate signal having an appropriate duty cycle ratio is applied from the gate drive circuit (Gx) to the switch element (Qx) so as to have an appropriate value according to the state of the lamp (Ld) at that time.

  Usually, in order to appropriately control the lamp current or voltage and power, the voltage of the smoothing capacitor (Cx), the voltage dividing resistor for detecting the current supplied from the smoothing capacitor (Cx) to the lamp (Ld), A shunt resistor is provided, and a control circuit is provided for allowing the gate drive circuit (Gx) to generate an appropriate gate signal, but these are omitted in FIG.

  When the lamp (Ld) is lit, the no-load open voltage is applied between the electrodes (E1, E2) for main discharge of the lamp (Ld) prior to starting. Since the input terminal (F1) and the ground terminal (F2) of the starter (Ue) are connected in parallel to the lamp (Ld), the same voltage as the voltage applied to the lamp (Ld) is applied to the starter (Ue). Is also supplied. In response to this voltage, the starter (Ue) charges the capacitor (Ce) via the resistor (Re).

  When the switching element Qe such as an SCR thyristor is turned on by the gate drive circuit (Ge) at an appropriate timing, the charging voltage of the capacitor (Ce) is applied to the primary winding (Pe) of the high voltage transformer (Te). Since the voltage is applied, a boosted voltage corresponding to the structure of the high voltage transformer (Te) is generated in the secondary winding (Se) of the high voltage transformer (Te). In this case, since the voltage applied to the primary winding (Pe) decreases rapidly with the discharge of the capacitor (Ce), the voltage generated in the secondary winding (Se) is also rapidly increased. Since the voltage decreases, the voltage generated in the secondary winding (Se) becomes a pulse.

  One end of the secondary winding (Se) of the high voltage transformer (Te) is connected to one electrode (E1) (in this case, the cathode) of the lamp (Ld), and the secondary winding of the high voltage transformer (Te). Since the other end of the wire (Se) is connected to an auxiliary electrode (Et) provided outside the discharge vessel (11) of the lamp (Ld), the secondary winding (Se) of the high voltage transformer (Te). The high voltage generated in the discharge is generated by dielectric barrier discharge between one electrode (E1) of the lamp (Ld) and the inner surface of the discharge vessel (11) of the lamp (Ld).

  When designing the starter (Ue), the peak value of the high voltage generated at the output terminal (F3) and the ground terminal (F2) of the starter (Ue) when the starter to which the no-load open circuit voltage is applied is operated. As described above, when the lamp (Ld) is at room temperature, the voltage Vtmin is set to 2 to 5 times the value necessary for starting the main discharge.

  Generally, the secondary side voltage of the transformer can be estimated by multiplying the primary side voltage by the primary and secondary turns ratio, but in this case, since it is a pulse as described above, The voltage waveform generated in the secondary winding (Se) is affected by the leakage inductance and parasitic capacitance of the high voltage transformer (Te). For this reason, the number of secondary windings (Se) of the high voltage transformer (Te) may be determined by trial manufacture of various windings.

  Whether or not the starter is properly designed is determined based on the peak value V1 of the voltage generated at the output terminal (F3) and the ground terminal (F2) of the starter (Ue) in the no-load state where the lamp (Ld) is not connected. When the lamp (Ld) at room temperature is connected, the voltage output capability of the starter can be limited, and the capability is gradually increased so that the probability of successful lamp start is approximately 50%. The peak value V2 of the voltage generated at the output terminal (F3) and the ground terminal (F2) of the starter (Ue) is measured, and it can be confirmed that the value obtained by dividing V1 by V2 is 2 to 5. it can.

  As a method for limiting the voltage output capability of the starter described above, a method of changing the turn ratio of the primary and secondary windings of the high voltage transformer (Te or Tk), or a power input terminal (F1) to the starter (Ue) 3), for example, a method using a variable voltage source (Vp) as shown in FIG. 3, and a zener diode is added in parallel with the capacitor (Ce) in order to clip the charging voltage of the capacitor (Ce). And controlling the timing at which the switch element (Qe) is turned on to control the voltage of the capacitor (Ce) at the moment when the switch element (Qe) is turned on, and is applied to the primary winding (Pe) of the high-voltage transformer. A voltage control method or a discharge gap (Ak) such as an arrester as shown in FIG. 13 is used, and this operating voltage defines the voltage output capability of the starter. For expression of the starter (Uk), wherein the operating voltage discharge gap (Ak) and the like can be used methods such as a method for exchanging different.

  Note that the starter (Uk) illustrated in FIG. 13 starts charging the capacitor (Cj) via the resistor (Rj). When the voltage of the capacitor (Cj) is charged up to a predetermined threshold voltage, the switch element (Qj) such as Sidac conducts itself and applies the voltage to the primary winding (Pj) of the transformer (Tj). The secondary side capacitor (Ck) is charged via the diode (Dj) connected to the secondary side winding (Sj). When the discharge of the primary side capacitor (Cj) progresses and the current becomes a predetermined value or less, the switch element (Qj) turns into non-conduction by itself, and charging of the capacitor (Cj) is started again. Every time the capacitor (Cj) is charged / discharged, the charge of the secondary side capacitor (Ck) is accumulated, and the voltage rises. When the voltage of the capacitor (Ck) is charged to a predetermined threshold voltage, a discharge gap (Ak) such as an arrester is turned on by itself, and the voltage is applied to the primary winding (Pk) of the transformer (Tk), A high voltage is generated in the secondary winding (Sk).

Although FIG. 4 shows the case where the high voltage of the starter is applied between the cathode side of the lamp and the auxiliary electrode, this may be applied between the anode side of the lamp and the auxiliary electrode.
FIG. 5 is a simplified further configuration example of the present invention. FIG. 4 shows the case where a starter (Ue) that generates a pulse high voltage is used. However, the starter (Uf) shown in FIG. 5 uses a case that generates a high voltage that rises relatively slowly. Indicates.

  As in the case of FIG. 4, since the input end (F1) and the ground end (F2) of the starter (Uf) are connected in parallel to the lamp (Ld), the no load applied to the lamp (Ld). The open circuit voltage is also supplied to the starter (Uf). In response to this voltage, the starter (Uf) starts charging the capacitor (Cf1) via the resistor (Rf). When the voltage of the capacitor (Cf1) is charged up to a predetermined threshold voltage, the switch element (Qf) such as Sidac conducts itself and applies the voltage to the primary winding (Pe) of the high voltage transformer (Tf). Then, the secondary side capacitor (Cf2) is charged via the diode (Df) connected to the secondary side winding (Se). When the discharge of the primary side capacitor (Cf1) progresses and the current becomes a predetermined value or less, the switch element (Qf) is turned non-conductive by itself, and charging of the capacitor (Cf1) is started again. Every time the capacitor (Cf1) is charged / discharged, the charging of the secondary side capacitor (Cf2) is accumulated, and the voltage rises.

One end of the capacitor (Cf2) is connected to one electrode (E1) (in this case, the cathode) of the lamp (Ld), and the other end of the capacitor (Cf2) is provided outside the discharge vessel (11) of the lamp (Ld). When the voltage of the capacitor (Cf2) reaches the discharge start voltage at that time, the discharge vessel of the lamp (Ld) one electrode (E1) and the lamp (Ld) is connected to the auxiliary electrode (Et). A discharge occurs due to dielectric barrier discharge between the inner surface of (11).
If this discharge occurs, the lamp starts, and the transition to arc discharge is successful, the voltage of the lamp (Ld), and hence the supply voltage to the starter (Uf), decreases, so that the capacitor (Cf1) The charging voltage is lowered and the switch element (Qf) is not operated.

When designing the starter (Uf), the maximum value of the high voltage generated at the output terminal (F3) and the ground terminal (F2) of the starter (Uf) when the starter to which the no-load open circuit voltage is applied is operated. As described above, when the lamp (Ld) is at room temperature, the voltage Vtmin is set to 2 to 5 times the value necessary for starting the main discharge.
Whether or not the starter is appropriately designed depends on the voltage V3 generated at the output terminal (F3) and the ground terminal (F2) of the starter (Uf) in the no-load state where the lamp (Ld) is not connected, and the room temperature. Starter (Uf) output terminal (F3) and ground when the voltage output capability of the starter is gradually increased with the lamp (Ld) in the state connected, and the probability of successful lamp start is approximately 50% The voltage V4 generated at the end (F2) is measured, and it can be confirmed that the value obtained by dividing V3 by V4 is 2 to 5.

Although FIG. 5 shows the case where the high voltage of the starter is applied between the cathode side of the lamp and the auxiliary electrode, this may be applied between the anode side of the lamp and the auxiliary electrode.
FIG. 6 is a simplified further configuration example of the present invention. In the circuit of FIG. 6, the switching element (Q1, Q2, Q3, Q4) such as FET is added to the circuit of FIG. An AC discharge voltage can be applied.
Each switch element (Q1, Q2, Q3, Q4) is driven by each gate drive circuit (G1, G2, G3, G4), and each gate drive circuit (G1, G2, G3, G4) is a full-bridge inverter. It is controlled by the full bridge inverter control circuit (Hc) so that the switches (Q1, Q4) (Q2, Q3) of the diagonal elements are simultaneously turned on.

The starter (Ue ′) is the same as the starter (Ue) in FIG. 4, but one end of the secondary winding (Si) is connected to the ground end (F2) in the starter (Ue) in FIG. In the starter (Ue ′), the output terminal (F3 ′) is directly connected to the wiring to one electrode (E1 ′) of the lamp (Ld ′).
The high voltage generated at the output terminal (F3, F3 ′) of the starter (Ue ′) is applied between one electrode (E1 ′) and the auxiliary electrode (Et) for main discharge of the lamp (Ld ′). Then, a discharge is generated by the dielectric barrier discharge between the one electrode (E1 ′) and the inner surface of the discharge vessel (11) of the lamp (Ld ′) to start the lamp.

  Note that if the switching state of the switch elements (Q1, Q2, Q3, Q4) of the full bridge inverter and the timing of the high voltage generation of the starter (Ue) are inconvenient in terms of timing from the viewpoint of starting discharge of the lamp. Is generated so that the switching of the conduction state of the switch elements (Q1, Q2, Q3, Q4) and the timing of the high voltage generation of the starter (Ue) are synchronized with each other. Alternatively, the operation of the full bridge inverter is stopped until the discharge start of the lamp is completed, thereby avoiding the timing inconvenience from the viewpoint of the discharge start of the lamp.

  Although not shown, the starter (Ue) in the circuit of FIG. 6 may be replaced with the starter (Uf) that generates a high voltage that rises relatively slowly as shown in FIG. Also in this case, one end of the secondary winding (Si) and the capacitor (Cf2) are connected to the ground end (F2) in the starter (Uf) of FIG. Directly connected to the wiring to the electrode (E1 ′).

FIG. 7 is a simplified embodiment of claim 1 of the present invention.
In this figure, the starter includes a starter transformer drive circuit unit (Ua) and a high voltage transformer circuit unit (Ub) including at least a high voltage transformer (Te). These circuit units (Ua, Ub) are obtained by dividing the starter (Ue) shown in FIG. 4, and the starter transformer drive circuit unit (Ua) is changed from the starter (Ue) to the high voltage transformer circuit unit (Ub). This is the part excluding. The high voltage transformer circuit unit (Ub) is installed separately from the power feeding circuit unit (By). The ground end (F1) of the starter (Ue) is divided into a ground end (F1 ′) of the starter transformer driving circuit unit (Ua) and a high voltage transformer circuit unit (Ub) ground end (F1 ″). A connection line (Kp) to the primary winding (Pe) of the high voltage transformer (Te) is extended.

  The wiring from the output terminal (F3) of the starter (Ue) shown in FIG. 4 to the lamp (Ld) auxiliary electrode (Et) transmits a high voltage pulse, whereas the connection line (Kp) is far more. Since the voltage is low, there is little concern that this connection line (Kp) will be adversely affected, that is, the possibility of noise radiation and the occurrence of dielectric breakdown in unintended parts is increased.

  FIG. 11 is a simplified embodiment of the second aspect of the present invention. In this figure, the lamp (Ld) and the high voltage transformer circuit part (Ub) of the starter are integrated to form a lamp house (Ly). The lamp house (Ly) includes a reflecting mirror (Y1) for outputting light emitted from the lamp in a specific direction, a light output window (Y2) covering the front surface of the reflecting mirror (Y1), and a power feeding circuit unit (By). A connector (Cn) for electrically connecting the lamp house (Ly) and the lamp house (Ly) is also shown as being integrated.

  FIG. 8 is a simplified embodiment of the lamp portion of the present invention. When the auxiliary electrode (Et) is provided in the discharge lamp so as not to be in contact with the discharge space (12) for main discharge, the auxiliary electrode (Et) is embedded in the discharge space surrounding portion (17), or the discharge space. Although it is possible to adopt an installation method such as contacting the outer surface of the surrounding portion (17) or arranging in the vicinity of the outer surface of the discharge space surrounding portion (17), both of FIGS. 8 (a) and 8 (b) An example of the structure in which the auxiliary electrode (Et) is installed in contact with the outer surface of the discharge space surrounding portion (17) of the lamp is shown.

  As shown in the figure, a pair of main discharge electrodes (E1, E2) are disposed opposite to each other in a discharge space (12) formed by a discharge vessel (11), and the main discharge electrodes. A discharge lamp (Ld) provided such that an auxiliary electrode (Et) other than the main electrode is not in contact with the discharge space (12) for main discharge, the discharge space surrounding the discharge space (12) of the discharge lamp (Ld) The conductor ring (Et1) whose peripheral length is shorter than the peripheral length of the thickest portion (90) of the outer shape of the surrounding portion (17) is greater than the thickest portion (90) of the outer shape of the discharge space surrounding portion (17). Conductor having a shorter perimeter than the perimeter of the thickest portion (90) of the outer shape of the discharge space enclosing portion (17), which is first installed on the side close to one of the electrodes (E1, E2) for main discharge The ring (Et2) is connected to the discharge space enclosure (1 The second conductor ring (Et2) is installed closer to the other side of the main discharge electrodes (E1, E2) than the thickest part (90) of the main conductor ring (90), and the first conductor ring (Et1) ) And the second conductor ring (Et2) by a conductor wire (W1) is used as the auxiliary electrode (Et).

  The above-described installation method of embedding in the discharge space surrounding portion (17) requires installation of the lamp discharge vessel by burner processing, and has the disadvantage that it takes time, and the discharge vessel material such as quartz glass is made of metal or the like. There is a drawback in that a risk of occurrence of cracks in the discharge vessel due to a difference in thermal expansion coefficient due to embedding of the auxiliary electrode material, that is, a different material.

  Further, the installation method arranged near the outer surface of the discharge space surrounding portion (17) requires a robust auxiliary electrode holding structure in order to determine the positional relationship between the lamp discharge vessel and the auxiliary electrode. The surface temperature of the lit lamp is about 1000 ° C., and the holding structure is required to have special heat resistance and mechanical accuracy. Furthermore, the installation of such a robust auxiliary electrode holding structure in the vicinity of the lamp shields the light emission of the lamp, so that there is a disadvantage that the efficiency of using the light emission of the lamp is lowered.

  On the other hand, in the case of the installation method of contacting the outer surface of the discharge space surrounding portion (17), for example, a method of winding a thin conductor wire around the discharge space surrounding portion (17), the discharge space surrounding portion (17) There are no drawbacks such as the installation method embedded in the inside and the disadvantage of causing the risk of occurrence of cracks in the discharge vessel, and there is no problem such as the installation method in the vicinity of the outer surface of the discharge space surrounding portion (17). There are no disadvantages of high cost and low efficiency of lamp light emission.

However, in the case of a lamp having a structure in which the discharge space surrounding part (17) has a structure in which the central part is swollen, the auxiliary electrode (Et) installation method by a method of winding a thin conductor wire is the main part of the lamp by dielectric barrier discharge. If an attempt is made to install the auxiliary electrode (Et), which is effective for starting the discharge, in the vicinity of the center of the discharge space enclosure (17), a serious problem occurs.
That is, since the central portion of the discharge space surrounding portion (17) is swollen, even if a thin conductor wire as an auxiliary electrode (Et) is wound around the discharge space surrounding portion (17), the wire wound by sliding is used for the main discharge. There arises a problem that the electrode moves in the direction of one of the electrodes (E1 or E2).

When this movement occurs, it means to move to the portion of the discharge space surrounding portion (17) or the sealing portion (13) having a cross-sectional area smaller than the cross-sectional area surrounded by the wound wire, so that the auxiliary electrode (Et ) And the discharge space surrounding portion (17) increases, and the effect for starting the main discharge of the lamp by the dielectric barrier discharge is reduced.
Further, when the movement of the auxiliary electrode (Et) exceeds the sealing portion (13) and reaches the external lead rods (21A, 21B), these are applied to the auxiliary electrode (Et). Since the voltage is short-circuited, there is a risk that the lamp cannot be started, and there is a risk of damage to the power supply circuit (Bx) or the like.

On the other hand, in the case of the installation method of the auxiliary electrode (Et) in FIG. 8, both conductor rings (Et1, Et2) sandwiching the thickest part (90) of the outer shape of the discharge space surrounding part (17). Are connected by a conductor wire (W1), so that the auxiliary electrode (Et) composed of these conductors (Et1, Et2, W1) is a dielectric barrier discharge for starting the main discharge of the lamp. As a result, there is an advantage that the inconvenience of deviating from a suitable position can be prevented.
The auxiliary electrode (Et) composed of the conductor wires (Et1, Et2, W1) is connected to the output end (F3) of the starter (Ue) through the connected conductor wire (We). These conductor wires should be made of a material having high heat resistance such as a tank stainless steel because the discharge vessel (11) during lamp operation becomes high temperature.

FIG. 9 is a simplified further embodiment of the lamp portion of the present invention. In FIG. 9, the external lead rod (21A) on the cathode side of the lamp (Ld) is connected to the ground end (F2) of the starter (Ue) and the ground output end (T2) of the feeder circuit (Bx), and the anode The external lead rod (21B) on the side is connected to the plus output terminal (T1) of the power feeding circuit (Bx).
On the other hand, the auxiliary electrode (Et) is connected to the output end (F3) of the starter (Ue) through the conductor wire (We), and is installed so as to surround the cathode side of the sealing portion (13). The conductor (Et3) is also connected via the conductor wire (W2). In FIG. 9, the conductor (Et3) installed so as to surround the cathode side of the sealing portion (13) is realized by a conductor coil wound around the cathode side of the sealing portion (13). Has been.

  Since the output terminal (F3) and the ground terminal (F2) of the starter (Ue) are connected to both ends of the secondary winding (Se) of the high voltage transformer (Te), the starter (Te) operates. During the lighting period, particularly after the lamp start is completed, no voltage is generated between the output terminal (F3) of the starter (Ue) and the ground terminal (F2).

  As described above, the external lead rod (21A) on the cathode side is connected to the ground end (F2) of the starter (Ue), and is a conductor (see FIG. Et3) is connected via the conductor wire (W2), the auxiliary electrode (Et), and the conductor wire (We), and therefore, during lighting, the external lead rod (21A) on the cathode side supplies the power supply circuit (Bx). Conductor installed so as to surround the connection point (Fz) between the starter (Ue) and the ground end (F2) in the wiring to the ground output end (T2) and the cathode side of the sealing portion (13). The same potential state as (Et3) is maintained.

By the way, in the lighting state of the lamp (Ld), the main discharge current of the lamp (Ld) flows through the path from the tip of the cathode (14) to the connection point (Fz) via the external lead rod (21A) on the cathode side. Therefore, a voltage drop proportional to the product of the resistance value of the path and the flowing current value is generated, and the potential increases as the tip of the cathode (14) is approached.
As described above, since the connection point (Fz) and the conductor (Et3) have the same potential, the cathode, particularly the portion near the sealing portion (13) has a higher potential than the surrounding conductor (Et3). Become.

  For this reason, as described in Japanese Patent Publication No. 4-40828, the discharge vessel (11) in the vicinity of the sealing portion (13) of the discharge vessel (11) of the lamp that has become hot in the lighting state is used. The impurity metal cation contained in the material is driven away from the electrode material constituting the cathode, and the impurity metal cation accumulates on the surface of the electrode material. Since the peeling phenomenon between the glass material such as quartz and the electrode material is prevented, the lamp is configured to have the structure shown in FIG. 9 to prevent the lamp from being damaged due to the peeling phenomenon. The effect of preventing it can be enjoyed.

  As shown in FIG. 5, the output terminal (F3) and ground terminal (F2) of the starter (Uf) are not directly connected to both terminals of the secondary winding (Sf) of the high voltage transformer (Tf). In addition, even when elements such as a diode (Df) and a resistor are inserted in series, no current flows or only a minute current flows between the output terminal (F3) and the ground terminal (F2). Therefore, even when the diode (Df) is inserted, the voltage drop (voltage when current flows in the forward or reverse direction) hardly occurs, and even when the resistor is inserted. Since the voltage drop hardly occurs, the above-described effect that the potential of the cathode, in particular, the portion near the sealing portion (13) is higher than that of the surrounding conductor (Et3) is effectively exhibited.

  FIG. 10 is a simplified further embodiment of the lamp portion of the present invention. In the lamp of FIG. 10, a pair of main discharge electrodes (E1, E2) are disposed opposite to each other in a discharge space (12) formed by a discharge vessel (11), and the pair of main discharge electrodes. A sealing portion is formed in which conductive metal bodies (20, 20A) for energizing the electrodes (E1, E2) are disposed, and a long conductive metal body (20A) is disposed in at least one of the sealing portions. Thus, an airtight seal portion (13A, 13B) is formed at two locations separated in the length direction, and an airtight space portion (25) is formed between the two airtight seal portions (13A, 13B), A discharge lamp (Ld) in which an auxiliary electrode (Et) other than the main discharge electrode is provided so as not to be in contact with the main discharge space (12), wherein the airtight space (25) At least partially facing The conductor (Et3) is installed outside the hermetic seal portion (13A and / or 13B), and the conductor (Et3) is electrically connected to the auxiliary electrode (Et). Is.

  In FIG. 10, the conductor (Et3) installed facing at least a part of the hermetic space (25) is realized by a conductor coil wound around the hermetic seal (13A and / or 13B). Has been. The airtight space (25) is formed in contact with a conductive metal foil (20A) made of molybdenum or the like for connecting the cathode (14) and the external lead rod (21A).

  As described in Japanese Patent Laid-Open No. 2000-348680, by providing the airtight space (25), the inner side of the hermetic seal portions formed at two locations of the sealing portion When the foil floats and the airtightness is lost, the mercury vapor in the discharge space (12) flows into the airtight space (25) and condenses, so that the pressure in the high pressure discharge lamp is greatly reduced. As a result, the discharge state of the high-pressure discharge lamp is not maintained, and the advantage that the high-pressure discharge lamp does not burst can be obtained.

And, a starter is connected between the auxiliary lead electrode (Et) and the external lead rod (21A) on the side where the airtight space (25) is provided in the bipolar electrodes (E1, E2) for the main discharge. By doing so, the embodiment of the present invention shown in FIG. 1010 can enjoy further advantages, as will be described below.
That is, the airtight space (25) and the discharge space (12) are connected by a conductor (that is, a conductive metal foil (20A) and a cathode (14)) in which the conductors in the space are connected in common. In addition, since the conductor outside the glass bulb is a commonly connected conductor (that is, they are connected by the auxiliary electrode (Et) and the conductor coil (Et3)), from the viewpoint of the starter, Two dielectric barrier dischargers are connected in parallel.

  Here, in the airtight space (25), the temperature when the lamp is turned on is kept lower than the discharge space (12), and the amount of mercury enclosed per unit volume is reduced or substantially none. In terms of pressure, the airtight space (25) is lower than the discharge space (12), and therefore when the starter generates a high voltage, the airtight space (25) is low. The part (25) is much easier to generate a dielectric barrier discharge. When this discharge occurs, ultraviolet rays are generated, and the generated ultraviolet rays pass through the hermetic seal portion (13A) and enter the discharge space portion (12), and ionize the gas in the discharge space portion (12). As a result, dielectric barrier discharge in the discharge space (12) is also likely to occur. That is, since the hermetic space portion (25) functions as a light excitation light source for the discharge space portion (12), the embodiment shown in FIG. 10 of the present invention has a high voltage value to be generated by the starter. You can enjoy great benefits that can be lowered.

  In the embodiment shown in FIG. 10, the airtight space (25) is formed in contact with the conductive metal foil (20A), but the extension of the electrode (14) or the external lead rod ( 21A) may be formed in contact with the extension. However, the thickness of the conductive metal foil (20A) is usually as thin as several tens of microns or less, and protrusions (or burr) such as burrs generated in the manufacturing process are formed on the edge portion (or The presence of the intentionally formed projections) has an effect of concentrating the electric field on the edge portion. Therefore, the hermetic space portion (25) is in contact with the conductive metal foil (20A), particularly on the edge portion. Forming in contact is advantageous from the viewpoint of facilitating the generation of the dielectric barrier discharge described above.

Further, in the embodiment shown in FIG. 10, the airtight space (25) is formed in the airtight seal portion on the cathode side, which is the same as that of the impurity metal positive electrode described in the embodiment shown in FIG. This is because it is preferable from the viewpoint of preventing a peeling phenomenon between the electrode material and a glass material such as quartz in the discharge vessel sealing portion due to ions. If this peeling phenomenon can be ignored or prevented by other means, the airtight space (25) may be formed in the airtight seal portion on the anode side.
Further, the function of the airtight space (25) that serves as a light excitation light source for the discharge space (12) is whether the voltage applied for the main discharge is direct current or alternating current. Regardless of whether the starter generates a high voltage pulse or generates a high voltage whose voltage rises relatively slowly, it works well.

It is the experimental result which measured the starter voltage and the non-restartable time about the lamp | ramp of different electrode spacing. It is the experimental result which performed the same measurement as FIG. 1 with respect to different no-load open circuit voltage. It is a structure of the experimental circuit for the measurement of FIG. 1 and FIG. It is the Example of the discharge lamp light source device of this invention which used the high voltage pulse starter by direct current lighting system. This is an embodiment using a DC starter in a direct current lighting system. It is an Example of the discharge lamp light source device which used the high voltage pulse starter by the alternating current lighting system. It is an Example of the discharge lamp light source device of this invention. It is an Example of the auxiliary electrode structure of the lamp | ramp of the discharge lamp light source device of this invention, (a) is an example, (b) is another example. FIG. 2 is an embodiment of a lamp having a conductor surrounding the cathode side of the sealing portion of the discharge lamp light source device of the present invention, where (a) shows the appearance and (b) shows a part of the cross section. It is an Example of the lamp | ramp which has the airtight space part of the discharge lamp light source device of this invention, (a) is an external appearance, (b) shows a cross section. It is an Example of the lamp house of the discharge lamp light source device of this invention. It is a block diagram of the conventional discharge lamp light source device. It is a starter figure using discharge gaps, such as an arrester.

Explanation of symbols

Mx DC power supply Bx power supply circuit Qx switch element Gx gate drive circuit Dx diode Lx choke coil Cx smoothing capacitor T1 plus output terminal T2 ground output terminal Vp variable voltage source Ue starter Ue 'starter Re resistance Qe switch element Ge gate drive circuit Ce capacitor Te High voltage transformer Pe Primary side winding Se Secondary side winding F1 Starter input end F2 Starter ground end F2 'Starter ground end F2 "Starter ground end F3 Starter output end F3' Starter output end F4 High voltage transformer circuit section input end Fh Lamphouse input terminal Fp Lamphouse high voltage transformer input terminal Fg Lamphouse ground terminal Fz Connection point Ld Discharge lamp E1 Electrode for main discharge E2 Electrode for main discharge Et Auxiliary electrode Uf DC star Rf Resistance Cf1 Capacitor Qf Switch element Tf High voltage transformer Pf Primary side winding Sf Secondary side winding Df Diode Cf2 Capacitor Q1 Switch element Q2 Switch element Q3 Switch element Q4 Switch element G1 Gate drive circuit G2 Gate drive circuit G3 Gate Drive circuit G4 Gate drive circuit Hc Full bridge inverter control circuit Ld 'Discharge lamp E1' Electrode for main discharge E2 'Electrode for main discharge By Feeding circuit section Ly Lamphouse Ua Starter transformer drive circuit section Ub High voltage transformer circuit Part We Conductor Wire W1 Conductor Wire W2 Conductor Wire Et1 Conductor Ring Et2 Conductor Ring Et3 Conductor Cn Connector Y1 Reflector Y2 Light Output Window 11 Discharge Container 12 Discharge Space Part 13 Sealing Part 13A Airtight Seal Part 13B Airtight 14 Electrode part 14 Cathode 15 Anode 17 Discharge space surrounding part 20 Conductive metal foil 20 A Conductive metal foil 21 External lead bar 21 A External lead bar 21 B External lead bar 25 Airtight space part 90 The thickest part of discharge space surrounding part Ni Feeder Ui Starter Ri Resistance Qi Switch element Gi Gate drive circuit Ci Capacitor Ti High voltage transformer Pi Primary side winding Si Secondary side winding K1 Feed line K2 Feed line Li Discharge lamp Rj Resistance Qj Switch element such as Sidac Cj Capacitor Tj transformer Pj primary winding Sj secondary winding Dj diode Ck capacitor Ak discharge gap of arrester Tk high voltage transformer Pk primary winding Sk secondary winding

Claims (2)

A discharge lamp (E1, E2) having a pair of main discharge electrodes (E1, E2) which are opposed to each other and contain a mercury of 0.15 mg or more per cubic millimeter of the volume of the discharge space (12) and the electrode interval is 2.5 mm or less. Ld), and a projector having a light source device to which a feeding circuit (Bx) for supplying a discharge current to the electrodes (E1, E2) for main discharge is connected,
An auxiliary electrode (Et) other than the electrode for the main discharge is provided so as not to be in contact with the discharge space (12) for the main discharge, and either of the bipolar electrodes (E1, E2) for the main discharge and the A starter circuit (Ue) that generates a high voltage is connected between the auxiliary electrodes (Et),
A projector characterized in that a high voltage generator (Ub) including at least a high voltage transformer (Te) of the starter circuit (Ue) is separated from a power feeding circuit (By). The projector according to claim 1, wherein the lamp (Ld) and at least the high voltage transformer (Te) of the starter circuit (Ue) are configured as an integrated unit.

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